Procurement Glossary
Tool approval: Process for quality assurance in production
November 19, 2025
Tool approval is a critical quality assurance process in procurement and production in which tools, molds and devices are systematically checked and approved before series production. This process ensures that all production equipment meets the specified requirements and can produce quality parts. Find out below what tool approval involves, which methods are used and how you can minimize risks.
Key Facts
- Systematic testing and approval of production tools before series production
- Includes dimensional measurements, material testing and functional verification
- Reduces quality risks and rework costs in series production
- Documents tool quality for supplier evaluation and audit purposes
- An integral part of series start-up management
Contents
Definition: Tool release
Tool approval refers to the structured validation process through which production tools receive their official approval for series use.
Core elements of tool release
The approval process comprises several key components:
- Dimensional measurement of all critical tool dimensions
- Material testing and hardness measurements
- Function test under production conditions
- Documentation of all test results
Tool approval vs. sampling
While prototype procurement creates the first functional samples, tool approval validates the final means of production. It takes place after mold construction and before the start of series production.
Importance of tool approval in Procurement
For procurement, tool approval is a key quality instrument that minimizes supplier risks and prevents production downtime. It forms the basis for tool deposits and supplier evaluations.
Methods and procedures
Tool approval follows standardized methods that ensure systematic and traceable validation.
Step-by-step release procedure
The approval process is divided into successive phases:
- Initial sample inspection with dimensional measurement
- Function test under production conditions
- Long-term test for wear assessment
- Final release documentation
Test criteria and standards
The evaluation is based on defined criteria such as dimensional accuracy, surface quality and service life. Industry-specific standards such as APQP or VDA are applied, which are also relevant in the series release process.
Digital documentation
Modern tool approvals use digital systems to record and manage all inspection data. This enables complete traceability and supports ramp-up management through rapid data evaluation.
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Important KPIs for tool approvals
Key figures enable the objective evaluation and continuous improvement of the tool release process.
Lead time KPIs
The release time from tool receipt to final release is a key indicator. Typical target values are 5-10 working days for standard tools. Delays indicate process weaknesses or supplier problems and influence ramp-up management.
Quality KPIs
The first release rate measures the proportion of tools released immediately without rework. Values above 85% are considered good, lower rates indicate quality problems. The number of release generations per tool is also recorded.
Cost KPIs
Release costs per tool and rework costs due to release errors are systematically recorded. These key figures support make-or-buy decisions and the evaluation of inspection service providers. Typical release costs amount to 2-5% of the tool costs.
Risks, dependencies and countermeasures
Tool release involves various risks that can be minimized by taking appropriate measures.
Quality risks
Incomplete or incorrect approvals lead to quality problems in series production. Defective tools produce rejects and jeopardize delivery deadlines. Countermeasures include standardized test plans and independent validation by external test laboratories.
Time risks in the project process
Delays in tool approval postpone the entire start of series production. Dependencies on mold making suppliers and complex tools are particularly critical. Risk minimization is achieved through buffer times and parallel release processes.
Supplier dependencies
Tool approval is heavily dependent on supplier capacity and expertise. Insufficient testing equipment or a lack of expertise on the part of the supplier can delay approvals. Feasibility reviews and supplier audits reduce these risks by checking competence at an early stage.
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Practical example
An automotive supplier carries out the tool release for an injection mold for the production of dashboard components. After delivery of the tool, all critical dimensions are measured using 3D coordinate measuring technology. Subsequently, 50 initial samples are produced and tested under series conditions. The parts undergo dimensional, form and surface tests as well as functional tests. After successful validation, the tool is released for series production and the documentation is sent to quality assurance and production.
- 30% reduction in start-up time thanks to structured release
- Avoidance of quality problems in series production
- Complete documentation for audit purposes
Current developments and effects
Tool approval is constantly evolving due to technological innovations and changing market requirements.
Digitalization and AI integration
Artificial intelligence is revolutionizing tool approval through automated image evaluation and predictive analyses. AI systems detect deviations faster than manual inspections and predict tool wear. This reduces inspection times and increases the accuracy of predictions for maintenance intervals.
Inline measurement technology
Integrated measuring systems enable continuous tool monitoring during production. This development shortens release cycles and supports ramp-up with real-time data on tool performance.
Sustainability aspects
Environmental awareness is increasingly shaping approval processes. Tool materials and coatings are tested for sustainability, while extended tool life reduces resource consumption. This also influences decisions between insourcing and outsourcing tool production.
Conclusion
Tool approval is an indispensable quality assurance process that contributes significantly to the success of series production. Systematic validation minimizes quality risks and prevents production downtime. Modern technologies such as AI and inline measurement technology are revolutionizing the approval process and enabling more efficient workflows. Companies should invest in structured approval processes in order to reduce costs in the long term and secure competitive advantages.
FAQ
What is the difference between tool approval and sampling?
Sampling validates initial prototypes and functional samples, while tool approval checks the final production tools before they are used in series production. It takes place later in the development process and focuses on the suitability for series production and quality capability of the tools.
Who is responsible for tool approval?
Responsibility typically lies with Procurement in collaboration with Quality Assurance and Production. The supplier provides the tool and test documentation, while the customer makes and documents the final release decision.
What are the costs for tool approval?
The costs include testing equipment, personnel, material consumption for samples and external testing services. They typically amount to 2-5% of the tool costs, but can be higher for complex tools. Investing in thorough approvals significantly reduces later quality costs.
How long does a typical mold release take?
The duration varies between 5-15 working days depending on the complexity of the mold. Simple molds can be approved more quickly, while complex multi-cavity molds or molds for safety-critical parts require longer inspection times. Parallel inspection processes can reduce the overall duration.
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